Walking welder



Nov. 24, 1953 E. R. POWELL 2,660,655

WALKING WELDER Filed Dec. 16, 1952 35 36 as r 6.50 58 24 22 INVENTOR [Zn .44 0 ffiO/VEZZ ATTORN EY Patented Nov. 24, 1953 WALKING WELDER Edward R. Powell, North Plainfield, N. .I., assignor to J ohns-Manville Corporation, New York, N. Y., a corporation of New York Application December 16, 1952, Serial No. 326,196

9 Claims.

The instant invention relates to resistance welding devices and particularly a hand guided welder of the walking type, i. e., a welder provided with means for moving it in steps across a work surface, the operator being required only to guide the device. The class of welding to which the device of the instant invention relates is commonly known as spot welding although the device may be adjusted to make a seam weld.

A primary object of the instant invention is to provide a portable, walking welder which is highly useful in making a uniform series of welds in work having either flat or irregular surfaces.

A further object of the present invention is to provide a walking welder with which a uniform series of welds can easily be made along irregular lines or along lines closely adjacent the edges of irregularly contoured work.

A further object of the present invention is to provide a walking welder in which the step length can be readily adjusted to make either a series of spot welds or a seam weld composed of a number of overlapping welds.

My invention will be more fully understood and further objects and advantages thereof will become apparent when reference is made to the more detailed description of a preferred embodiment of the invention which is to follow and the accompanying drawings in which:

Fig. 1 is an elevation of a preferred embodiment of the apparatus of the instant invention;

Fig. 2 is an elevation of the apparatus of Fig. 1 as seen from the right; and,

Fig. 3 is a diagrammatic illustration of the operation of a part of the apparatus of Figs. 1 and 2.

Referring to the drawings, there is shown a piece of work 2 consisting of two sheets of metal, for example steel or chrome-nickel alloy, supported on a ground plant 4. An electrode 6, adjustably supported in a bracket 8, is shown contacting the upper surface of work 2, the electrode 6 and the ground plate 4 being connected to a conventional source of welding current (not shown) as by leads 9. Bracket 8 is attached to the lower end of a normally upright frame H] which also carries a mechanism for actuating a foot piece :2.

The mechanism for actuating foot piece I 2 may be of any type designed to move the foot piece relative to electrode 6 in general directions both perpendicular to and parallel with the surface of work 2. A convenient form of such a mechanism is shown in the drawings and consists of a rod member M to the lower end of which is attached the foot piece I2, the rod being provided with a slot l6 for receiving a pin l8 adjustably fixed to the frame IS. The pin it is provided with a fixed collar 2% located between the frame NJ and rod Id. The portion of pin It extending through slot is preferably unthreaded and a portion thereof to the left of rod id (Fig. 2) is threaded and adapted to receive a washer E2, overlying slot i6, and a nut 2 for maintaining the washer in position. The washer i2 is maintained at a distance from collar 26 which provides for a smooth sliding and pivotal motion of rod l'fl about pin it. A threaded portion of pin it extends through a slot 26, provided in the frame It, there being provided on such threaded portion a nut 28 which, in conjunction with collar 2G, fixes the position of pin 18 along slot 25 at any desired point. The foot piece i2 is shown forwardly of the electrode but obviously may be positioned to one side thereof.

The upper end of rod I4 is provided with a bearing 38 for receiving one arm of a crank 32 attached to crankshaft $4. Shaft 3:1 is journalled in bearings 36 supported by bracket means 38 from the frame l0. Fixed to shaft 3% is a cam arranged to actuate a switch when crankarm 32 extends generally away from foot piece l2, i. e., when electrode 5 contacts the surface of work 2. The switch 37 actuates a control relay or other devices (not shown) controlling the flow of current to leads 9 in a known manner. Also fixed to shaft 3 is a gear it) engaged by worm 42, which is driven by a motor it. The motor is supported by any convenient bracket means it from the frame It] and is connected to a suitable source of electrical energy by means of leads ii. Ahand grip 48 is provided at the upper end of frame iii and a horizontal hand rod so may also be provided to aid the operator in manipulating the devices.

In operation, the device is disposed over the work in approximately the aspect shown and the motor 44 is energized. Worm 52 drives gear to turn crankshaft 3d and crank With the arrangement shown, crank 32 will move the upper end of rod l4 over a substantially circular path. The effect of this circular motion on foot piece i2 is diagrammatically illustrated in Fig. 3, wherein points 52, 5'4 and 5% correspond to positions of pin l8 and curves 53, 55, and 5? are the paths, relative to electrode 8 over which foot piece 32 will travel for the various positions of pin it. Paths 53, 55 and 5? have the same center 59 and vertical axis 60, but the lateral axes difier in length. Thus adjustment of pin [8 merely changes the step length. The axes of the paths also represent components extending generally perpendicular to and parallel with the work sur face and it will be understood that these com-- ponents of foot piece motion will cause walking if the perpendicular component is of sufficient length to cause lifting of electrode 5.

In Fig. 1 of the drawing, the pin I8 is shown in a position similar to position 55 in the diagram of Fig. and, with the setting shown, foot piece 12 will tavel, relative to electrode 6, over an elliptical path having a relatively short lateral or parallel component. An ideal disposition of the device in relation to a horizontal work surface is one in which the end of electrode 6 is horizontally aligned with a central point of the vertical or perpendicular component of the path traveled by the foot piece. When the device is so disposed, the foot piece I! will contact the surface of work 2 during its travel through the lower half of the path and will lift electrode 6 from contact with the surface. During the travel of foot piece 12 along the upper half of the path, the electrode a will be in contact with the surface and foot piece 12 will be out of contact therewith. Since the path traveled by foot piece l2 relative to electrode 6 includes a component extending generally laterally of the electrode, or parallel to the work surface, the electrode '5 will be moved in a direction generally parallel to the work surface while the foot piece is in contact with the surface and during travel through the upper half of the path the foot piece, in effect, takes a step. If it is desired to move the electrode B only a short distance over the surface, the pin i8 is lowered on the frame It and for longer steps it is raised. It will be iuiderstood that the distance at which the foot piece is spaced from the electrode affects the amount of tilting of frame in which will render the action of foot piece l2 ineffective to cause Walking.

The size relationship and spacing between the electrode, foot piece and work has been somewhat exaggerated, for clarity of illustration. It will be understood that the device of the instant invention is particularly adapted for making a series of closely spaced or overlapping, relatively small welds in foil-like sheets, and, consequently, in practice the axes of the path over which the foot piece travels will be relatively short and the foot piece 52 and electrode 6 will be spaced relatively close together. With such an arrangement the device may be readily used to weld together corrugated or irregularly contoured pieces, and may easily be guided along irregular lines having sharp bends or angles therein. The device may be guided along a line closely adjacent the edge of an irregularly shaped piece of work.

Having thus described my invention in rather full detail, it will. be understood that these details need. not be strictly adhered to and that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by subjoined claims.

What I claim is:

1. In a welding apparatus, an electrode having an end portion disposed for contact with a surface of work to be welded, a foot member adjacent said electrode and movable relative thereto over a path having components extending generally perpendicular to and parallel with said surface, and means for moving said foot member into and out of contact with said surface along said path, said generally perpendicular component being of sufficient length to lift said electrode from contact with said surface.

2. In a welding apparatus, an electrode having an end portion disposed for contact with a surface of work to be welded, a frame fixedly sup porting said electrode, a foot member mounted on said frame and movable relative to end portion over a path having components extending generally perpendicular to and parallel with said surface, and means carried by said frame for moving said foot member into and out of contact with said surface along said path, said generally perpendicular component being of sufflcient length to lift said end portion from contact with said surface.

3. The apparatus defined in claim 2 wherein said path is substantially elliptical.

4. The apparatus defined in claim 2 wherein said path is substantially circular.

5. The apparatus defined in claim 2 and including means for adjusting the length of said parallel component.

6. In a welding apparatus adacted to be supported by a work surface, a frame, an electrode attached to said frame and having a work contacting portion, a foot member movably mounted on said frame for movement into and out of engagement with said surface, and means for moving said foot member over a path having components extending generally parallel with and perpendicular to said surface, said work contacting portion being aligned with a central point of said perpendicular component.

'7. In a welding apparatus, a frame, an electrode attached to said frame and adapted to contact a surface of work to be welded, a rod mem ber slidably and pivotally connected at a midpoint thereof to said frame, a foot piece at one end of said rod member adapted to contact said surface, and means for repeatedly moving the other end of said rod member over a circular path to repeatedly move said foot piece into and out of contact with said surface.

8. The apparatus defined in claim. '1, including means for adjusting the position of said midpoint along the length of said rod member.

9. In a welding apparatus, a frame, electrode attached to said frame and depending therefrom, a rod member having a foot piece at one end thereof adjacent said electrode, means slidably and pivotally connecting a mid-point of said rod to said frame, means for adjusting the distance between said mid-point and one end of said rod, a crankshaft mounted for rotation on said frame, a crank on said crankshaft pivotally connected to the end of said rod opposite said foot piece for moving said rod lengthwise, a cam on said crankshaft arranged to actuate a welding current control switch when said crank points away from said foot piece, and means for rotating said crankshaft.

EDWARD R. POWELL.

References Cited in the his 01 this patent UNITED STATES PATENTS Numb er 

